Cabals and tribunals work better when leadership falls onto those with leadership qualities; being proactive, creative, charismatic, and so on. I disagree with giving incentives for leaders and leaders alone. However, I
agree with the general gist that activity needs to be promoted.
When I first read this thread, I held back from posting right away so I can get some thoughts into it, and I cannot come up with any refreshing ideas other than the
Cohort System (Achernar, 07) that's already been suggested. Something
similar could be implemented for cabals, tribunals and even religions in that regard, a system that counts raw numbers, disregarding status.
Then again, I am not sure an exclusive system is necessary when Cohort System is implemented. Leaders are usually more known, by natural selection more charismatic (or wouldn't last), and tend to be followed anyway. Thus both the leaders' and their followers' online hours should increase.
Waiting for something to be implemented in SK is of course akin to the wait of Starcraft 2 and World of Warcraft expansions.